External Transmit-Receive PTT switch for linear and transceiver

External Transmit-Receive PTT switch for linear and transceiver

Having been given an Icom IC-2E 2-metre transceiver and finding it had better receive qualities than my AKD-2001 transceiver. I decided it could take pride of place first in the Micro-shack in my Dining Room and later in the main shack itself.

There were some snags to solve first however. The first was that the IC-2E was now 20+ years old and its battery pack didn’t want to get up out of its long sleep. It also has max output of 1.5w which could be a challenge. So I decided the answer lay in feeding it through my Mirage B108 linear amp to get 10w out. There was a further problem, however because the Mirage Linear’s transmit sensing doesn’t switch on until 3w input!

I decided to build an external Transmit-Receive switch to switch Press-To-Talk on the Mirage B108 linear amp and the Icom IC-2E simultaneously. The circuit also steps power down from 13.8v to 9v for the Icom.

Transmit - Receiver Switch Circuit

 

Layout

As I use a electret desk microphone it was necessary to have a high value resistor across the mic socket so that the PTT switch activates the transceiver’s PTT circuit.

Here is the PTT box in situ in my Dining Room stealth station with the linear and transceiver.

External transmit-receive switch